Circuit breaker closing mechanism



June 30, 1964 A. s. cAswELL CIRCUIT BREAKER CLOSING MECHANISM 5 Sheets-Sheet 1 Filed Dec. ll, 1959 June 30, 1964 A. s. cAswELL CIRCUIT BREAKER CLOSING MECHANISM 5 Sheets-Sheet 2 Filed Dec. 1l, 1959 INVENTOR THU/ S. Gua/ELL NNE June 30, 1964 A. s. cAswELL CIRCUIT BREAKER CLosINC MECHANISM Filed Dec. l1, 1959 5 Shets-Sheet 3 m F L F ou C .L 0 a, S1 'l Rf o mm M7 M I J N4 e ma @y m fr kr, mf m, W Cr m n H a H A M m June 30, 1964 A. s. cAswELL CIRCUIT BREAKER CLOSING MECHANISM 5 Sheets-Sheet 4 Filed DeC. ll, 1959 June 30, 1964 A. s. cAswELL 3,139,494

CIRCUIT BREAKER CLOSING MECHANISM Filed Deo. 1l, 1959 5 Sheets-Sheet 5 IN V EN TOR. Her/we J. 6mm/LL STROLENK, 5455@ 65e@ Sol-FEM contacts are brought into engagement.

United States Patent O1 lce 3&3955294 Patented .lune 30, 1964 3,139,4Q4 CHlCUT EREAKER CLOSWG MECHANISM Arthur S. Caswell, Greensburg, Pa., assigner to I-T-E Irrcuit Breaker Company, Philadelphia, Pa., a corporation ot Pennsylvania Filed Dec. 11, 1959, Ser. No. 859,003 15 Claims. (Cl. 20th-92) The instant invention relates to circuit interrupters ingeneral and more particularly to circuit interrupters which are power operated to the closed position thereof.y

In circuit breakers of the prior art a solenoid operated mechanism has often been utilized as the closing means. The solenoid operator presents a severe insulation problem when used in across-the-line service especially in the high voltage range, say 15 kv. and above. Further, the solenoid control circuits are so arranged that the solenoid current is abruptly interrupted as the'circuit breaker This interruption of highly inductive solenoid coil current induces eX- tremely high voltages and is diicult to interrupt with a small inexpensive switch.

When a remote source of control power is to be used the same solenoid closing coil could not be used. Therefore, the same motivator cannot be used on both acrossthe-line and remote power without changing the solenoid.

Motor operated closers of theprior art were operated from a remote lowvoltage power supply; Thus, circuit interrupters utilized for high voltage applications which were motor operated required a low voltage source of power to operate the closing motor. In the case of an automatic recloser, if the control power failed, the recloser could not automatically reclose and restore primary power to the line.

This invention solves the previously noted problems by utilizing a universal A.C., D.C. motor as the motivator for closing. A simpley means is provided for changing the motor operating power from an internal across-theline service to an external remotely controlled source. The means is such that isolation between the primary power and the secondary power supply is simplified, made more dependable as well as economical, and the transfer from one source ofy power to another is inherently interlocked and fool proof.

The means comprises a simple switching :device for yselectively connecting the universal motor to a remote source of control power or to the primary power through a transformer. For applications in which oil is utilized as an interrupting medium the transformer is immersed in the oil so that the oil aiords insulation and isolation from the high voltage primary source. The transformer may be of an inexpensive construction so as'to have a y high core loss` which produces heat thereby eliminating the necessity for theseparate heater which is presently utilized in cold climates.

The universal motor operates the contacts of the circuit interrupter into engagement by ldriving a cam through a clutch mechanism with the cam in turn operating a colapsible linkage. A trip latch normally maintains the collapsible linkage in an extended position and when in this position the operation of the cam vis effective to close the circuit breaker.

The cam is also provided with a formation which serves as a prop latch for the collapsible linkage when the circuit breaker is closed. When the cam has reached a predetermined position in the closing operation, that is, after the contacts are engaged, means operated by thel cam causes the clutch to disengage the driving connection between the cam and universal motor so that no braking means for the motor is required.

Another feature of the instant invention is the ynovel arrangement of the current carrying elements of the three phases of a circuit breaker. The cooperating contacts are housed within a tank having a cylindrical portion. The interrupters of `all three phases are positioned on a line parallel to the diameter of the cylindrical tank portion so that all three phases are readily ganged for simultaneous operation. To maintain voltage clearances, corresponding elements of two phases are positioned on one side of the previously mentioned line while the corresponding elements of the third phase are disposed on the other side of this line. With this arrangement the best utilization of available space is obtained.

Accordingly, a primary object of the instant invention is to provide a novel closing mechanism for a circuit interrupter which is operable from both A.C. and D.C. power sources and includes means for selective operation from either an acroSs-the-line or remote power supply.

Another object is to provide a novel circuit breaker closing mechanism which utilizes a cam device for posithe linkage.

A further object is to provide a multi-phase circuit interrupter in which the current carrying elements thereof are arranged in a novel configuration so as to simplify the mechanical interconnections between phases and obtain the best utilization of available space.

These as well as other objects of the instant invention shall become readily apparent after reading the following description of the accompanying drawings in which:

FIGURE 1 is a side elevation of the circuit breaker with the near side of the tank cut away to reveal the closing mechanism which is in the tripped position prior to resetting. In FIGURE 1, for the sake of clarity, only the center phase of the circuit breaker is illustrated.

FIGURE 1A illustrates the elements of the operating mechanism when the circuit breaker is closed.

FIGURE 1B is an enlarged view illustrating the operating mechanism in the reset position.

FIGURE 2 is a plan view of the circuit breaker of FIGURE 1 with the lid casting and mechanism cover plate partially cut away to reveal the internal mechanism.

FIGURE 3 is a partial elevation of the operating mechanism in the reset position looking in the direction of arrows 3 3 of FIGURE 1. f

FIGURE 4A is a plan view of the clutch cam plate.

FIGURE 4B is an elevation of the clutch cam plate FIGURE 4A looking in the direction of arrows 4B- FIGURE 5 is a wiring diagram of a closing circuit for across-the-line service.

FIGURE 6 is a wiring diagram of a closing for operation rom a remote source of power.

FIGURE 7 is a wiring diagram of a closing circuit for both across-the-line service and service from a remote source.

`Now referring to the figures, circuit breaker 10 is a three-phase unit each phase of which is provided with an identical current path which comprises current stud 11, interrupter unit 12, conducting strap 13, series overload device 14 and current stud. 15. Interrupter units 12 are disposed within cylindrical tank 16 which is provided with removable cover 17.

Current studs 11 and 15, in passing through cover openings 18, 19, respectively, are surrounded by insulating bushings 20, 21, respectively. The portions of bushings 20, 21 disposed within tank 16 are covered by ground shields 22, 23 respectively with two current transformers 24, 25 surrounding ground shields 23.

The interrupter units 12 of all three phases are evenly spaced along line 125 which is parallel to a diameter of cylindrical tank 16. As best seen in FIGURE 2, corresponding elements of the outer phases are mounted to face in the same direction while elements'of the center phase are mounted in a direction displaced 180 as compared to the corresponding elements of the outside phases. This provides space in tank 16 opposite the center phase to place operating mechanism At each side of mechanism 30, and assembled to cover 17, is a box enclosure 29 for the complete timing and closing control auxiliary switch, operation counter, and visible position indicator (not shown) as well as for closing motor 28. Shaft 27, connected to mechanism 30 at pivot 50 by links 98, 99 joined at pivot 97, projects into enclosure 29 to operate the required components therein in a manner well known to the art.

Motor 28 (FIGURE 3) is a universal A C., D.C. motor which serves to provide the motivating force for the closing of circuit breaker 10. 'Ihe output shaft of motor 28 drives the input of a set of reduction gears 31 whose output drives miter gear 32 which is keyed to shaft 33. Miter gear 32 in turn drives miter gear 34, keyed to shaft portion 35 which carries clutch member 36 thereon.

Clutch member 37, keyed to shaft portion 38, is biased by compression spring 39 toward engagement with clutch member 36. Shaft portions 35 and 38 are axially aligned and form a single shaft 35, 38. Gear 34 and clutch member 36 are integrally formed and are free to rotate with respect to shaft portion 35 except when clutch members 36, 37 are in operative engagement. Shaft 35, 38 includes a portion 38a of square cross-section which provides a rotational axis for closing cam 40 mounted thereon.

Cam 40 is a plate-like member whose edge 41 is in operative engagement with cam roller 42 mounted to one end of guidearm 43 whose other end is mounted to stationary pivot 44. From here the closing force is transmitted through the collapsible toggle linkage comprising links 45, 46 to interrupter contact operating lever 47. One end of link 45 is mounted to guide arm 43 at pivot 48 about which cam roller 42 is rotatable. The other end of linkr 45 is joined to one end of link 46 at the knee 49 of toggle linkage 45, 46 while the other end of link 46 is pivotally mounted at tie rod 50 to operating lever 47 In the reset position of mechanism 30 (FIGURE 1B), toggle linkage 45, 46 is restrained against collapsing by trip linger 51 pivoted to stationary pivot 52. Finger 51 provides a trip latch whose free end engages roller 53 at one end of link 54. The other end of link 54 is keyed to stationary shaft 55 to which one end of link 56 is also keyed; The other end of link 56 is pivoted at 57 to one end of link 58 whose other end is joined to toggle linkage 45, 46 at knee 49.

Operating lever 47 is pivoted intermediate the ends thereof about pin 59 with the long endof lever 47 operating through tie rod 60 and links 61 to move rods 62 of interrupter units 12 downwardly during closing of circuit breaker 10. The lower end of rods 62 carry the movable contact means of interrupters 12 in a manner well'known to the art.

During closing travel of lever 47, opening springs 63 operative over the full closing stroke, are charged. Springs 63 are housed in a pair of guide tubes 64 with each spring 63 bearing against the end 65 of its respective guide tube and movable plate 66 disposed within the guide tube 64. Flexible cables 67 are connected at one of the ends thereof to plates 66 and at the other of the ends thereof to tie rod 60 passing over guide pulleys 68 in the process.

Mechanism30 also includes a pair of quick opening springs 69Y disposed within a housing formed of twosections 70, 71, for a purpose to be hereinafter explained. Y

Section '70 is mounted for limited movement with respect to section 71 through pins 72 and a pair of elongated slots (not shown). At the last limited amount of the closing stroke the short rounded end of arm 47 near pivot 59 picks up housing portion 70 to compress 69 in the housing portion 71 which is fixedly mounted to cover 17 at projections 73.

In order to move mechanism 30 from the reset position of FIGURE 1B to the closed position of FIGURE 1A, cam 40 is rotated in a counterclockwise direction. In the travel of cam 40 when the high point 72 thereof engages cam roller 42, limit adjusting screw 73 strikes upturned arm 74 of clutch cam plate 75 (FIGURES 4A and 4B) causing rotation of plate 75 and shaft 38 about its pivot opening 76 which is mounted upon a rounded hub portion 77 of cam 40. l

As cam plate rotates counterclockwise the cam action of plate edge 78, in engagement with roller 79, causes the support crank arm 80 for roller 79 to pivot clockwise with respect to FIGURE 3 about pin 81. Crank arm 80 is keyed to pin 81 as are arms 82 whose free ends engage shoulder 83 of clutch member 37 to move clutch member 3'7 against the force of biasing spring 39 to allow closing motor 28 to coast to a stop. Suitable limit switches 104 (FIGURES 5-7) are provided to deenergize motor 28 when cam 40 is in a predetermined angular position as when roller 42 is at a position clockwise of high point 72. Prior to the disengagement of clutch members 36, 37, cam roller 42 rolls into low formation 84, adjacent to high point 72, which serves as a prop latch for circuit breaker 10 which is now in the closed position.

Travel limit adjusting screw 73 is adjusted to separate clutch parts 36, 37, immediately after cam roller 42 passes high point 72 on cam 40. At this point the load on the clutch teeth drops making declutching easier withY less stress on the parts involved.

After the camming action of surface 78 or plate 75, roller 79 falls into recess formation 84 of plate 75 to maintain arms 82 in the position wherein clutch parts 36, 37 are disengaged.

With a trip impulse emanating from control box 29 and received by trip shaft 52, in a manner well known to the art, trip finger 51 is rotated in a counterclockwise direction with respect to FIGURE 1B releasing roller 53 which in turn releases links 54, 56, 58 to free the knee 49 of toggle 45, 46. The ever present pull on links 54, 56, 58 exerted by opening springs 63 when circuit breaker 10 is closed forces the knee of toggle 45, 46 to collapse to the right with respect toVFIGURE lA to its position of FIGURE l.

With toggle linkage 45, 46 collapsed, the heavy load on cam roller 42 is released. Tension spring 85, mounted between stationary pin 86 and pin 87 on guide arm 43, assisted by torsion spring 88, mounted on shaft 38, acts to rotate cam 40 in a clockwise direction to the reset` position of FIGURE 1B. Two return springs 85, 88 are sary speed. Spring 85 is useful where the cam slope is steep and is provided to assure the return of links 45, 46 and the resetting of trip latch roller 53 before reengaging of the clutch 36, 37. This provides fast closing and prevents false operation.

As cam 40 rotates clockwise at the end of its travel to the reset position block 89 strikes upturned arm 99 of clutch cam plate 75 rotating it clockwise and releasing roller 79 which falls into recess 89a which is more deeply cut than Arecess 85. Arms 82 release clutch part 37 allowing spring 39 to force clutch part 37 into engagement with clutch part 36.

i The quick opening springs 69 have a strong but limited stroke and are utilized to overcome starting inertia, contact friction, and oil resistance to obtain a rapid parting of the contacts comprising interrupters 12. T he followthrough springs 63 in tubes 64carry the opening motion through untiltie rod 6i) strikes the resilient buffer 91 mounted to the inside of cover 17 and thereafter hold operating lever 47 in the open position.

Now referring more particularly to FIGURE 5 which illustrates a circuit for across-the-line operation which includes a step-down transformer 11M) having aprimary winding 101 connected across one phase of circuit breaker 10. The low voltage secondary Winding 102 of transformer 100 is utilized to energize a series circuit comprising the armature of motor 28. Motor series field 1113, a set of cooperating contacts 104 which are opened at the end of the closing stroke, a set of cooperating contacts in control box 29 for timing reclosing and for lockout in a manner well known to the art, a set of cooperating contacts 106 that check the main latch roller 53 to prevent a closing cycle from being initiated before the trip latch 51 is reset, holding coil 150 and normally open contacts 151 whichV parallel closing switch 11@ to maintain motor 28 energized until a closing cycle is completed. Transformer 100 is mounted at the bottom of tank 16 on supports (not shown). Transformer lill) may be of an inexpensive. construction so as to have high core losses which. generate heat to warm the oil which occupies tank 16 and serves as an interrupting medium.

.In the embodiments of FIGURES 6 and 7,` reference numerals previously utilized in describing FIGURE 5 are utilized to designate like elements performing substantially the same functions. FIGURE 6 illustrates a circuit` for closing from a remote power `source of low voltage, either A.C. or D.C. Which is connectable to terminals 1fl7, 198. The remote control' circuit of FIG- URE 6 comprises the armature of motor 28, series field windingl 103, holding coil normally closed sets of contacts 104, 105 and 106 as well as remote closing switch 120 paralleled'by holding contacts 115.

In FIGURE 7 the concepts illustrated in FIGURES 5 and 6 are combined to provide a means for selectively operating the mechanism from the primary power source or a low voltage source of secondary control power. The circuit of FIGURE'7 includes a series circuit extending between terminals 111, 112 which comprises the armature of motor 28, seriesiield Winding 103 and contacts 194, 105, 106.

Terminals 111, 112 form the pivot points for contact arms 113, 114, respectively. Spring 116 biases plunger 117 of'solenoid 115 to the left with respect to FIGURE 7 and also biases contact arms 113, 114 into engagement with terminals 118, 119, respectively. The low voltage secondary winding 102 of transformer 100 is connected through holding coil 150e and closing switch 11d, paralleled by contacts 151a to terminals 118, 119. With contact arms 113, 1 14 inengagement with terminals 118, 119 operation is as illustrated in FIGURE 5. The .circuit of FIGURE 7 further includes remote closmg switch 120 connected in series with holding coil 15% and paralleled by rholding contacts 15112. When switch 120 is closed line 121 is connected to line 122 with line 122 being connected to one terminal of a secondary control power source whose other terminal is adapted to be connected to line 123. Lines 121, 122, 123 are connected to'terminals 124, 125, and 126, respectively, while solenord co1l 127 is connected between terminals 124 and 126. When closing switch 120 is operated,solenoid plunger 117 moves to the vright with respect to FIGURE 1 moving with it contact arms 113, 114 which now engage contacts 12S, 126, respectively, to interlock the system against` v starting fromprimary power. With contact arms 113,Y

114 in this position operation is as illustrated in FIG- URE 6.

While they have not been illustrated, it is to be understood that suitable lead openings are provided in tank 16 for the conductors of the circuitry illustrated in FIG- URES 5-7. l

Thus, I have provided a novel closingr mechanism for a circuit breaker which is cam operated and in which the operating cam serves as a prop latch to maintain the circuit breaker in the closed position. My invention also provides a novel configuration for the current carrying elements of the circuit breaker whereby optimum utilization of tank space is obtained and further provides a motivator and energizing means therefore whereby operation may be obtained from primarypower of a remote source of A.C. or D.C. power.

Although I have here described preferred embodiment of my novel invention, many variations and modifications will now be apparent to those skilled in the art, and I therefore prefer to be limited, not by the specific disclosure herein, but only by the appending claims.

I claim:

1. A circuit breaker comprising a pair of cooperating contacts and a mechanism operatively connected to said cooperating contacts for operating said contacts into engagement; said mechanism including a collapsible linkage, a first latch means engaging an intermediate portion of said linkage for maintaining said linkage in an extended position, and a motor driven cam means operable upon an end of said linkage to effect operation of said contacts into engagement; said cam means integrally including a formation constructed and positioned to provide a second latch means abutting said end of said collapsible linkage for maintaining said linkage when extended in a position such that said contacts are engaged.

2. A circuit breaker comprising a pair of cooperating contactsand a mechanism operatively connected to said cooperating contacts for operating said contacts into engagement; said mechanism including a collapsible linkage, a first latch means for maintaining said linkage in an extended position, and a motor driven cam means operable upon said linkage to effect operation of said contacts into engagement; said cam means including a formation constructed and positioned to provide a second latch means for maintaining said linkage when extended in a position such that said contacts are engaged; said linkage comprising a first link, a second link, and a pivotal knee connection joiningsaid first and said second links; said first latch means connected to said linkage at said knee connection; a first end of said linkage operatively connected to said contacts and a second end'of said linkage in operative engagement with said cam means.

3. A circuit breaker comprising a pair of cooperating contacts and a mechanism operatively connected to said cooperating contacts for operating said contacts into engagement; said mechanism including a collapsible linkage, a first latch means for maintaining said linkage in an extended position, and a cam means operable upon said linkage to effect operation of said contacts into engagement; said cam means including a formation constructed and positioned to provide a second latch means for maintaining said linkage when extended in a position such that said contacts are engaged; said linkage comprising a first link, a second link, and a pivotal knee connection joining said first and said second links; said first latch means connected to said linkage at said knee connection; a first end of said linkage operatively connected to said contacts and al second end of said linkage in.

operative engagement with said cam means; said cam means comprising a rotatable plate-like member having its edge in operative engagement with said second end of said linkage. f Y

4. A circuit breaker comprising a pair of cooperating contacts and a mechanism operatively connected to said cooperating contacts for operating said contacts into engagement; said mechanism including a collapsible linkage, a first latch means for maintaining said linkage in an extended position, and a cam means operable upon said linkage to effect operation of said contacts into engagement; said cam means including a formation constructed and positioned to provide a second latch means for lmaintaining said linkage when extended in a position such that said contacts are engaged; said linkage comprising a first link, a second link, and a pivotal knee connection joining said first and said second links; said first latch means connected to said linkage at said knee connection;.a first end of said linkage operatively connected to said contacts and asecond end of said linkage in operative engagement with said cam means; said cam means comprising a rotatable plate-like member having its edge in operative engagement with said second end of said linkage; an electric motor and first means operatively connecting said motor to said plate-like member to impart rotation thereto about an axis normal to the plane thereof.

5. A circuit breaker comprising a pair of cooperating contacts and a mechanism operatively connected to said cooperating contacts for operating said ,contacts into engagement; said mechanism including a collapsible linkage, a first latch means for maintaining said linkage in an extended position, and a cam means operable upon said linkage to effect operation of said contacts into engagement; said cam means including a formation constructed and positioned to provide a second latch means for maintaining said linkage when extended in a position such that said contacts are engaged; said linkage comprising a first link, a second link, and a pivotal knee connection joining said first and said second links; said first latch means connected to said linkage at said knee connection; a first end of said linkage operatively connected to said contacts and a second end of said linkage in operative engagementwith said cam means; said cam means comprising a rotatable plate-like member having its edge in operative engagement with said second end of said linkage; an electric motor and first means operatively connecting said motor to said plate-like member to impart rotation thereto about an axis normal to the plane thereof; said electric motor constructed for operation from both an A.C. and a D.C. source of electrical energy.

6. A circuit breaker comprising a pair of cooperating contacts and a mechanism operatively connected to said cooperating contacts for operating said contacts into engagement; said mechanism including a collapsible linkage, a first latch means for maintaining said linkage in an extended position, and a cam means operable upon said linkage to effect operation of said contacts Vinto engagement; said cam means including a formation constructed and positioned to provide a second latch means for maintaining said linkage when extended in a position such that said contacts are engaged; said linkage comprising a first link, a second link, and a pivotal knee connection joining said first and said second links; said first latch means conneoted to said linkage at said knee connection; a first end of said linkage operatively connected to said contacts and a second end of said linkage in operative engagement with said cam means; said cam means comprising a rotatable plate-like member having its edge in operative engagement with said second end of said linkage; an electric motor and first means operatively connecting said motor to said plate-like member to impart rotation thereto about an axis normal to the plane thereof; said first means including a clutch, biasing means urging said clutch to an engaged position, and release means constructed to operate said clutch to a disengaged position; means engageable with said release means to effect operation of said clutch to said disengaged position when said plate-like member is in a predetermined angular position wherein said contacts are engaged if said linkage is extended.

7. A circuit breaker comprising a pair of cooperating contacts and a mechanism operatively connected to said cooperating contacts for operating said contacts into engagement; said mechanism including a collapsible linkage, a first latch means engaging an intermediate portion of said linkage for maintaining said linkage in an extended position, and a cam means operable upon an end of said linkage t effect operation of said contacts into engagement; said cam means integrally including a formation constructed and positioned to provide a second latch means abutting said end of said collapsible linkage for maintaining said linkage when extended in a position such that said contacts are engaged; an electric motor and first means operatively connecting said motor to said cam means for imparting rotational motion thereto which operates said contacts into engagement.

8. A circuit breaker comprising a pair of cooperating contacts and a mechanism operatively connected to said cooperating contacts for operating said contacts into engagement; said mechanism including a collapsible linkage, a first latch means for maintaining said linkage in an extended position, and a cam means operable upon said linkage to effect operation of said contacts into engage-A ment; said cam means including a formation constructed and positioned to provide a second latch means for maintaining said linkage when extended in a position such that said contacts are engaged; an electric motor and first means operatively connecting said motor to said cam means for imparting motion -thereto which operates said contacts into engagement; said first means including a clutch, biasing means urging said clutch to an engaged position, and release means constructed to operate said clutch to a disengaged position; means engageable with said release means to effect operation of said clutch to Asaid disengaged vposition when saidcam means is in a predetermined position wherein said contacts are engaged if said linkage is extended.

9. A circuit breaker comprising a pair of cooperating contacts and a mechanism operatively connected to said cooperating contacts for operating said contacts into engagement; said mechanism including a collapsible linkage, a first latch Ameans for maintaining said linkage in an extended position, and a cam means operable upon said linkage to effect operation of said contacts into engagement; said linkage comprising a first link, a second link, and a pivotal knee connection joining said first and said second links; said first latch means connected to said linkage at said knee connection; a first end of said linkage operatively connected to said contacts and a second end of said linkage in operative engagement with said cam means; an electric motor and first means operatively connecting said motor to said cam means for imparting motion thereto which operates said contacts into engagement; said first means including a clutch, biasing means urging said clutch to an engaged position, and release means constructed to operate said clutch to a disengaged position; means engageable with said release means to effect operation of said clutch to said disengaged position when said cam means is in a predetermined position wherein said contacts are engaged if said linkage is ex-l tended.

10. A circuit breaker comprising a pair of cooperating contacts and a mechanism operatively connected to said cooperating contacts for operating said contacts into ensecond links; said first latch means connected to said linkage at said knee connection; a first end of said linkage operatively connected to said contacts and a second end of said linkage in operative engagement with said caml means; an electric motor and first means operatively connecting said motor to said cam means for imparting motion thereto which operates said contacts into engagement;

said electric motor constructed for operation fromV both an A.C. and a D C. sourceV of electrical energy.

ll. A circuit breaker comprising a pair of cooperating contacts, a mechanism including a motivating means operatively connected to said cooperating contacts for operating said contacts into engagement, and a universal electric motor for actuating said motivating means; a step-down transformer; means connecting the primary thereof for energizat-ion by a high voltage source of electrical energy to which said circuit breaker is connected; said transformer having a secondary; means for operatively connecting said secondary to said motor for energization thereof; circuit means adapted to be connected to a low voltage source of electrical energy; and switch means selectively connecting said motor to one of said secondary and said circuit means rfor energization of said motor; said switch means including automatic means alternately connecting said motor from said circuit means to said secondary means responsive to tailureof said circuit means.

12. A circuit breaker comprising a pair of cooperating contacts, a pivotallyfmounted arm operatively connected to said contacts to control their movement between an engaged and a disengaged position; collapsible toggle linkage comprising first and second links pivotally joined to one another; a rotatable cam; said toggle linkage connected between said cani and said arm, irst latch means; connecting means operatively connected between said iirst'latch means and a stationary pivot; said lirst latch means abutting the knee of said toggle linkage for holding said linkage in any extended position, said toggle linkage being adapted to move said contacts to said engaged position under control ot said cam when said linkage is in said extended position.

13. A circuit breaker comprising a pair of cooperating contacts, a pivotally mounted arm operatively connected to said contacts to control their movement between an age comprising first and second links pivotally joined to one another; a rotatable cam; said toggle linkage connected between said cam and said arm, r'st latch means;

connecting means operatively connected between said firstA latch means and a stationary pivot; said rst latch means abutting the knee of said toggle linkage for holding said linkage in an extended position, said toggle linkage being adapted to move said contacts to said engaged position under control of said cam when said linkage is in said extended position; a universal motor for rotating said cam; a step-down voltage transformer circuit means connected between said motor and a high voltage source of electrical energy to which said circuit breaker is connected for energizing said transformer.

15. A circuit breaker comprising a pair of cooperating contacts, a pivotally mounted arm operatively connected to said contacts to control their movement between an engaged and a disengaged position; collapsible toggle linkage comprising lirst and second links pivotallyV joined to one another; a rotatable cam; said togglelinkage connected between said cam and said arm, first latch means;

engaged and a disengaged position; collapsible toggle linkage comprising rst and second links pivotally joined to one another; a rotatable cam; said toggle linkage conrnected between said cam and said arm, first latch means;

contacts, a pivotally mounted arm operatively connected to said contacts to control their movement between an engaged and a disengaged position; collapsible toggle linkconnecting means operatively connected between said first latch means and a stationary pivot; said iirst latch means abutting the knee of said toggle linkage for holding said linkage in an extended position, said toggle linkage being adapted to move said contacts to said engaged position under control of said cam when said linkage is in said extended position; a tank containing a high dielectric fluid; said circuit breaker being positioned in said tank and immersed in said tiuid.

References Cited in the tile of this patent UNITED STATES PATENTS 1,643,444 Burnham Sept. 27, 1927 1,902,396 De Ferranti Mar. 21, 1933 2,068,402 Duiling et al. Jan. 19, 1937 2,521,194 Van Ryan Sept. 5, 1950 2,640,122 Oppel et al. May 26, 1953 2,697,149 Wallace et a1 Dec. 14, 1954 2,698,888 Coe Ian. 4, 1955 2,698,916 Coe Jan. 4, 1955 2,821,600 Ridgley Jan. 28, 1958 2,836,769 Sandin May 27, 1958 2,891,122 Froland June 16, 1959 2,892,057 MacNell et al June 23, 1959 2,905,787 Heintz Sept. 22, 1959 2,959,655 Mitchell Nov. 8, 1960 

1. A CIRCUIT BREAKER COMPRISING A PAIR OF COOPERATING CONTACTS AND A MECHANISM OPERATIVELY CONNECTED TO SAID COOPERATING CONTACTS FOR OPERATING SAID CONTACTS INTO ENGAGEMENT; SAID MECHANISM INCLUDING A COLLAPSIBLE LINKAGE, A FIRST LATCH MEANS ENGAGING AN INTERMEDIATE PORTION OF SAID LINKAGE FOR MAINTAINING SAID LINKAGE IN AN EXTENDED POSITION, AND A MOTOR DRIVEN CAM MEANS OPERABLE UPON AN END OF SAID LINKAGE TO EFFECT OPERATION OF SAID CONTACTS INTO ENGAGEMENT; SAID CAM MEANS INTEGRALLY INCLUDING A FORMATION CONSTRUCTED AND POSITIONED TO PROVIDE A SECOND LATCH MEANS ABUTTING SAID END OF SAID COLLAPSIBLE LINKAGE FOR MAINTAINING SAID LINKAGE WHEN EXTENDED IN A POSITION SUCH THAT SAID CONTACTS ARE ENGAGED. 